Oscillating Tool: Variable Speed Doesn't Work
If the variable speed doesn't work on your oscillating tool, locate these parts and check for damage: the circuit board, carbon brush, and speed control switch. Consider fixing your tool yourself. Check out our repair guide for tips on how you can get your tool back up and running again, saving you on having to hire an expensive service. Refer to your owner's manual for detailed instructions for your model.
Carbon Brushes
The carbon brushes ride on the commutator, supplying power to the armature. Worn out, or damaged, carbon brushes may not be able to keep up with changing power demands. To check the condition of the carbon brushes, remove the brush caps and pull out the brushes. Brushes should be free from cracks, chips, uneven wear or anything else out of the ordinary. Brushes should not be less than 1/8 of an inch. If they are, replace them. Insert the carbon brushes into the housing and screw the brush caps back on. Note: on some models, you will have to open the housing to gain access to the carbon brushes.
The carbon brushes ride on the commutator, supplying power to the armature. Worn out, or damaged, carbon brushes may not be able to keep up with changing power demands. To check the condition of the carbon brushes, remove the brush caps and pull out the brushes. Brushes should be free from cracks, chips, uneven wear or anything else out of the ordinary. Brushes should not be less than 1/8 of an inch. If they are, replace them. Insert the carbon brushes into the housing and screw the brush caps back on. Note: on some models, you will have to open the housing to gain access to the carbon brushes.
Find your Carbon Brushes here
Switches
The speed control switch controls the speed of the motor. If you make adjustments to the speed, but the speed does not change, then your speed control switch is faulty. The following repair procedure will vary on all models as they are different, but will be similar. To change the speed control switch, open the housing of the tool. You may have to remove the screw securing the power cord clamp. Locate the speed control switch. Take a picture of the wire attachments or make note of where they connect. Disconnect the wires from the switch and then clean out the housing of any dust and debris. Attach the wires to the new switch, referring to your picture. Install the new speed switch into the housing and reattach the clamping screw for the power cord and reassemble the housing back together.
The speed control switch controls the speed of the motor. If you make adjustments to the speed, but the speed does not change, then your speed control switch is faulty. The following repair procedure will vary on all models as they are different, but will be similar. To change the speed control switch, open the housing of the tool. You may have to remove the screw securing the power cord clamp. Locate the speed control switch. Take a picture of the wire attachments or make note of where they connect. Disconnect the wires from the switch and then clean out the housing of any dust and debris. Attach the wires to the new switch, referring to your picture. Install the new speed switch into the housing and reattach the clamping screw for the power cord and reassemble the housing back together.
Find your Switches here
Circuit Board
Some models will have a circuit board that controls the oscillating tool when you turn it on and adjust the speed. Over time, and with use, these circuit boards can short out or suffer from other problems that can impact the operation of the tool. To check and replace a circuit board, remove the brush caps and pull out the carbon brushes. Open the oscillating tool housing and locate the circuit board. Make sure all of the wires are attached to the circuit board, before further diagnostics. Pull the circuit board out and examine it for burn marks, melting, broken components or anything else out of the ordinary that may indicate that the circuit board is defective. If the circuit board is defective, take a picture or make a diagram of the wire connections for attaching to the new circuit board. Remove the old wires from the circuit board and...
Some models will have a circuit board that controls the oscillating tool when you turn it on and adjust the speed. Over time, and with use, these circuit boards can short out or suffer from other problems that can impact the operation of the tool. To check and replace a circuit board, remove the brush caps and pull out the carbon brushes. Open the oscillating tool housing and locate the circuit board. Make sure all of the wires are attached to the circuit board, before further diagnostics. Pull the circuit board out and examine it for burn marks, melting, broken components or anything else out of the ordinary that may indicate that the circuit board is defective. If the circuit board is defective, take a picture or make a diagram of the wire connections for attaching to the new circuit board. Remove the old wires from the circuit board and attach on the new one. Reinstall into the housing and reassemble the housing back together. Install the brushes with the caps.
Read More
Find your Circuit Board here
